The author of ‘Unstable Majorities’ argues that if the electorate seems fickle, it’s because the politicians are too ideological.

By James Taranto

Most observers of American politics predict 2018 will favor the Democrats. The party has a good chance of taking control of the House in November, and even a Senate majority is within reach, although Democrats are defending three times as many seats in the upper chamber as Republicans are.Here’s a safer prediction: If the Democrats do triumph on Nov. 6, they and their supporters will emerge triumphalist, proclaiming their majority permanent and President Trump a lame duck. Ten months in advance, Morris P. “Mo” Fiorina has a bucket of cold water to throw on such claims.Mr. Fiorina—no relation to 2016 presidential candidate Carly Fiorina or her husband—is a 71-year-old Stanford political scientist and author of a new book, “Unstable Majorities: Polarization, Party Sorting and Political Stalemate.” As the title suggests, he believes the U.S. has entered an era in which no party can hold a majority for very long. “We can change our pattern of government every two years,” he tells me on a recent visit to the Journal’s offices, “and we started doing that.”Did we ever. The party controlling the House, Senate or White House changed in seven of the nine elections between 2000 and 2016—the only exceptions being the presidential re-election years, 2004 and 2012. “I sort of trace it back to ’92, the end of the Republican presidential era, and then ’94 is the end of the Democratic congressional era,” Mr. Fiorina says. Those were long eras. Republicans held the White House for 20 of the 24 years following the 1968 election. The Democrats dominated Congress for the better part of a lifetime: During the 62-year period after the 1932 election, the party had a majority in the House for 58 years and the Senate for 52 years. The Democrats took the House in 1954 and held it for 40 years straight.

Illustration: Ken FallinThose old enough to remember the decades before the ’90s, then, may tend to see permanent majorities around the corner because they expect a return to normalcy. Mr. Fiorina, by contrast, argues that frequent shifts in political control are now the norm because of the way the parties have changed. He rejects the common view that American voters are “polarized.” Instead, he says, the parties have become polarized, in a process he calls the “sorting” of the electorate.“We have these two now cohesive, different parties,” he says. Democrats and Republicans today are as ideologically distinct as “the Social Democrats and the Christian Democrats in Europe at the height of their power in the 20th century. And the problem is, we’ve got a much more heterogeneous country, and there’s only two of them, and they just don’t fit the electorate.”He arrives with a PowerPoint presentation that visualizes the data behind his theory. A pair of bar graphs show the ideological distribution of lawmakers in the 87th Congress (1961-63) and the 111th (2009-11). In both eras Democrats were the liberal party and Republicans the conservative one. But the pattern is markedly different: In 1961-63, both parties’ lawmakers tended to cluster in the middle. In 2009-11, there were two clusters—Democrats to the left, Republicans to the right. “There’s no longer any overlap at all,” Mr. Fiorina says. “The center is empty. That hasn’t happened in the electorate.”A line graph illustrates the electorate’s continuity. The share of Americans identifying as politically moderate has remained fairly constant—around 40%, and usually a plurality—since at least 1974. In the same period, another chart shows, independents overtook Democrats as the biggest partisan grouping. As the parties drifted from the ideological middle, centrist voters disaffiliated from the parties.That creates what Mr. Fiorina calls “the ping pong pattern” of unstable majorities. One party manages “to win, narrowly, and then they immediately respond to their base. So Bush says we’re going to have personal Social Security accounts, and voters—some say, ‘I didn’t vote for that.’ Or Obama says we’re going to do government health care, and a lot of them say, ‘I didn’t vote for that.’ ” Lawmakers from the party in power “suffer for it in the next election, when they lose the marginal voters,” as Republicans did in 2006 and Democrats in 2010.That seems plausible enough, but there’s an obvious complication: Most legislation that makes it through Congress, even on a party-line vote, is not all that extreme ideologically. Take health care. Mr. Fiorina pulls up a chart titled “Issue Centrists Still Dominate,” based on data from the American National Election Studies. It shows that in five issue areas, the centrist position is by far the most popular.“This would be single payer right here—these 12%,” Mr. Fiorina says, pointing to one end of the health-care distribution. At the other end, the “leave-everything-to-the-market people” are approximately as numerous. The peak, at 28%, is right in the center. “On issue after issue, it doesn’t matter what you ask, people sort of clump up in the middle,” he says. “Goldilocks—they want some of both.”But isn’t that what they got with ObamaCare? The Affordable Care Act shifted policy leftward, but nowhere near the extreme of single payer. Its central element, the recently repealed individual mandate, was first proposed by the Heritage Foundation in 1989 as a “market-based” alternative to more-statist approaches, including outright socialization. Similarly, the tax reform Congress enacted last month won only Republican votes, but it was hardly an exercise in ideological extremity. Even Barack Obama had said corporate rates should be lower. (As for George W. Bush’s Social Security idea, it was never written into legislation.) Mr. Fiorina answers this conundrum by referring me to the work of another political scientist, Frances Lee of the University of Maryland. She has a theory to explain why the minority party balks. “Frances talks about how if you have two closely balanced parties that are fighting for the majority in every election, they change their strategy, and this all becomes position-taking and trying to embarrass the other party, and it’s not about legislating,” he says. “They’re perfectly prepared to shift positions on a dime if it embarrasses the other party, because the payoff now is the electoral victory and not legislative.” To judge by their book titles, Mr. Fiorina and Ms. Lee are kindred spirits. His is “Unstable Majorities,” hers “Insecure Majorities: Congress and the Perpetual Campaign.”If unstable majorities are a problem, what might be the solution? In parliamentary systems with proportional representation, a multiplicity of parties represent a spectrum of views and often govern in coalitions. That won’t work in the U.S., Mr. Fiorina says, because “the majoritarian electoral system and the Electoral College” ensure that “only two parties can really compete.”What should a party do if it aspires to an enduring majority? “Go back to being a more sort of open—no litmus tests,” Mr. Fiorina advises. “The Democrats are all talking about their chances of winning next time, but if you keep trying to run antigun and pro-choice candidates in areas like West Virginia . . . you’re committing suicide.”This advice has one crucial shortcoming, Mr. Fiorina acknowledges: “They can’t do it.” One reason has to do with money. “The donors are most ideological of all,” he says. In the 1970s and ’80s, “a big majority of contributions to congressional races came from individual contributions within your district, and now the money is coming from outside. Texas is an ATM for Republicans, California and Manhattan for Democrats.” He adds that “30 years ago, an Ohioan Republican and an Oregon Republican would have faced very different primary electorates that run different kinds of races. Now, you look at their campaigns—they’re going to be the same. They’re getting their money from the same kinds of people.” The Republican in Oregon, a more liberal state, is likely to prove unelectable. For this problem there is probably no remedy. “The only thing I can see mattering would be unconstitutional,” Mr. Fiorina says—to wit, a law requiring that “all campaign contributions have to come from within the jurisdiction of the race being held.”Then again, there is Donald Trump. He won the Republican presidential nomination against several opponents with more money and far stronger ideological credentials. His victory demonstrates, according to Mr. Fiorina, that partisan sorting “at the Bill Kristol level”—meaning among pundits and intellectuals—“is way higher than the sorting at the level of even the primary voters.”Mr. Fiorina holds out some hope that Mr. Trump will break the ping pong pattern. “In the book, I characterize Trump first as a de-sorter and then as sort of a disjunctive president, and in Silicon Valley terms a disrupter,” he says. “I thought if there’s a positive on Trump, it would be his potential to disrupt both parties.”So far, though, Mr. Fiorina finds the president’s policies too conventionally conservative. “My ideal scenario originally was that Trump would come in and propose a big infrastructure bill, which would split the Republicans and split the Democrats,” Mr. Fiorina says. “He didn’t do that.”When I ask what Mr. Fiorina thinks will happen this November, he demurs: “I could make a case for a Democratic wave, a Democratic disappointment, or anything in between, but I don’t put high probability on any of the scenarios.”One of his observations, however, is suggestive of a wave. “The incumbency advantage is all but gone,” he says. “The incumbency advantage has been declining in House elections since the ’80s, and it was at 2% in the last election. People are voting—however they vote for president, they vote for the House as well.”That doesn’t mean all incumbents are vulnerable. A Democratic lawmaker in a heavily Democratic district, for example, will almost certainly win. The diminution of the incumbent advantage simply means that, all else being equal, a Democrat in an open-seat race would likely win by almost as wide a margin as an incumbent. In the 1980s, Mr. Fiorina says, incumbency per se was good for 10 to 12 points on average. Nowadays, “how your president is doing” matters much more.In 2017 there were special elections for five House seats vacated by Republicans—in Kansas, Montana, Georgia, South Carolina and Utah. The GOP held all five, but all its candidates underperformed the previous incumbents’ 2016 margins of victory, by between 5 and 25 points. If Mr. Fiorina is right about the diminution of the incumbent advantage, these results would seem to bode ill in November for Republicans—incumbent or not—in marginal districts.On the other hand, if the Republicans do get wiped out this year, there’s a good chance they’ll stage a comeback in 2020. Or 2022 at the latest.Mr. Taranto is the Journal’s editorial features editor.

If you know the other and know yourself, you need not fear the result of a hundred battles.

Sun Tzu

We are travelers on a cosmic journey, stardust, swirling and dancing in the eddies and whirlpools of infinity. Life is eternal. We have stopped for a moment to encounter each other, to meet, to love, to share.This is a precious moment. It is a little parenthesis in eternity.